
The Date Entry Assistant Dialog is available for use with all date fields, to make it easy to enter complex date information. You can access it by double-clicking on any date field, or by clicking on the little button to the right of the date field.
The dialog has 5 tabs for entering 5 different kinds of date specifiers:
With fact dates (dates of events or attributes, displayed in the Facts tab of the Property Box), you can optionally also enter a separate sort date.